Adhere To The Manufacturer’s Specifications For Trouble-Free Service

For decades, GSC propellers have been used on tractor and pusher aircraft, gyrocopters, airboats, powered parachutes, and powered paragliders. They provide excellent thrust and performance, and when installed correctly will continue to prove themselves as the best propellers on the market today. As with any specialized equipment, installation as well as care and use, must closely adhere to the manufacturer’s specifications. This will result in many hours of trouble-free service.

GSC Service Bulletin - May 17, 1999

May 17, 1999 - GSC Systems Service Bulletin

Affected Models: All GSC Systems 2 and 3 made ground adjustable

GSC Systems has been in the business of producing quality propellers for over 30 years, for many types of aircrafts. Over the course of these 30 years, it is possible that the original aircraft and/or the GSC propeller may have changed ownership several times. During the transfer of ownership often the instructional and maintenance procedures of our propellers have been lost. To that end, many propellers receive incorrect maintenance.

The most critical assembly procedure of our propellers are that the hub and root ends not be tighten past the recommended 100 in/lb torque specification. It is also possible that due to the over tightening of the attach bolts, that the space between the aluminum hub halves is not longer visible. The result of this improper assembly or maintenance could result in premature blade failure resulting in either injury or death.

If you do not presently have a set of GSC assembly instructions, please contact GSC Systems and one will be forwarded to you.

Required Service: Immediate Inspection

Inspect to insure that a visible gap between the aluminum hub halves is detected. If no gap is visible, contact GSC Systems.

If you are the initial and original owner of a GSC Propeller, are you certain that the hub has never been torqued past the 100 in/lb MAX specifications, if not please contact GSC Systems

If you are not the original owner of a GSC Propeller, can you be assured that the GSC Propeller hub has never been torqued past the 100 in/lb MAX specification? If not, please contact GSC Systems

GSC Systems TBO

GSC Systems have documented user times over 1000 hours but due to the nature of the exchange and selling of our product we are implementing a 500 or 5 year TBO for all GSC propellers.

If you require further information, please feel free to contact GSC Systems. Our goal is to continue the supply of a quality and safe product.

Aluminium Roots End Assembly

Pitch Settings

Standard Black Root Ends

Questions And Answers

Do I NeeD To Balance My Propeller?

If you have a brand new propeller, there is no balancing necessary. All propellers are final balanced at the factory. If, however, you have altered your prop in any way, then balancing may be necessary. Propellers must be balanced using a proper balancing method, not simply by weight.

What's The Easiest Way To Install My Propeller?

The multi-blade propeller is easily assembled on a flat working area (following assembly instructions). All bolts are finger-tight only at this time. The propeller can then be mounted on the prop flange on the aircraft, and pitch can be set while on the aircraft using the GSC Pitch Adjusting Tool.

How Do I Use The GSC Pitch Adjusting Tool?

Complete assembly and use instructions are provided with each tool. The downloadable Pitch Setting diagrams and instructions on this page will help you in setting pitch using GSC Pitch Adjusting Tool.

What Is The Recommended Torque On All The Bolts?

All bolts, when using the GSC blades with black composite root ends, are to be torqued no more than 100 in/lbs. or 8.5 ft/lbs. Blades with aluminum root ends can be torqued more.

Should I Check The Tracking On My GSC Prop?

Yes, you should check the tracking of all blades while they are installed on the aircraft. The tolerance of the blade tracking is 1/8" at the tip. Blade tracking can be manipulated slightly by applying forward or aft pressure on the appropriate blade while torquing bolts.

Should There Be A Gap Between My Hub Halves?

Yes, the propeller hubs are designed to have a 30 thousandths gap when the round root end of the blades are placed inside. Do not over-torque bolts until the gap disappears. Torque to a maximum of 100 in/lbs. ONLY!

I Can No Longer See A Gap Between My Hub Halves. Should I Be Concerned?

There should always be a slight gap. This design is to give a clamping action to the blades and not allow them to change pitch in flight. Our experience has shown that a lack of gap is usually the result of over-torquing.

I Have A Multi-Blade Propeller Which Is Quite Old. Can I Replace Just One Blade?

Yes, we can replace just the one blade. However, if the propeller is more than two years old, the new blade may not balance with the old blades and it will be necessary to return the old blades and have us balance the new blade to them.

I Seem To Be Getting A Vibration From My Prop, What Do I Do?

Double-check your tracking (tolerance of 1/8" at tip). Double-check the pitch of your prop (variance from blade-to-blade should not be more than ½ degree). If propeller has been altered in any way, balancing may be necessary. If vibration still persists, it could be from another source, such as engine crankcase or gearbox issue. Simply call GSC Systems for advice.

What Do Those Numbers Mean, Which Are Stamped On My Blades?

The numbers are reference balance numbers which GSC uses in their balancing method. They should be quoted when ordering replacement blades. It is important that in a set of blades for a particular prop, these numbers all be the same.